<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>边框盒子</title>
		<style>
			.box {
				width: 400px;
				height: 250px;
				background-color: pink;
				border: 2px solid red;
				padding: 10px;
				/* 设置为边框盒子：即使设置了内边距和边框，也不影响最终的宽高 */
				box-sizing: border-box;
			}
		</style>
	</head>
	<body>
		<div class="box">这是盒子模型</div>
	</body>
</html>